Bio-nanocomposite films based on cellulose nanocrystals filled polyvinyl alcohol/chitosan polymer blend Nassima El Miri, 1,2 Karima Abdelouahdi, 3 Mohamed Zahouily, 1 Aziz Fihri, 2 Abdellatif Barakat, 4 Abderrahim Solhy, 5 Mounir El Achaby 5 1 Facult e des Sciences et Techniques, Universit e Hassan II-Casablanca, Casablanca 20650, Morocco 2 MAScIR Foundation, Rabat Design, Rue Mohamed El Jazouli, Madinat Al Irfane 10100 Rabat, Morocco 3 Division UATRS, Centre National pour la Recherche Scientifique et Technique (CNRST), Angle Allal Fassi/FAR, Hay Riad, 10000 Rabat, Morocco 4 INRA, UMR 1208 Ing enierie des Agropolyme `res et Technologies Emergentes (IATE) 2, 34060 Montpellier Cedex 1, France 5 Universit e Mohammed VI Polytechnique, Lot 660-Hay Moulay Rachid, 43150 Ben Guerir, Morocco Correspondence to: A. Solhy (E - mail: abderrahim.solhy@um6p.ma) and M. El Achaby (E - mail: mounir.elachaby@um6p.ma) ABSTRACT: Bio-nanocomposite films based on polyvinyl alcohol/chitosan (PVA/CS) polymeric blend and cellulose nanocrystals (CNC) were prepared by casting a homogenous and stable aqueous mixture of the three components. CNC used as nanoreinforcing agents were extracted at the nanometric scale from sugarcane bagasse via sulfuric acid hydrolysis; then they were characterized and successfully dispersed into a PVA/CS (50/50, w/w) blend to produce PVA/CS–CNC bio-nanocomposite films at different CNC con- tents (0.5, 2.5, 5 wt %). Viscosity measurement of the film-forming solutions and structural and morphological characterizations of the solid films showed that the CNC are well dispersed into PVA/CS blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and CNC, thus improving their properties. The obtained bio-nanocomposite films are mechanically strong and exhibit improved thermal properties. The addition of 5 wt % CNC within a PVA/CS blend increased the Young’s modulus by 105%, the tensile strength by 77%, and the toughness by 68%. Herein, the utilization of Moroccan sugarcane bagasse as raw material to produce high quality CNC has been explored. Additionally, the ability of the as-isolated CNC to reinforce polymer blends was studied, resulting in the production of the aforementioned bio-nanocomposite films with improved properties. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42004. KEYWORDS: biopolymers and renewable polymers; blends; composites; mechanical properties; properties and characterization Received 24 September 2014; accepted 17 January 2015 DOI: 10.1002/app.42004 INTRODUCTION Recently, more attention has been given to natural polymers with a focus on sustainable development and environmental preserva- tion. 1 Following this tendency, the attempt has been made to replace polymers derived from petroleum with superior biode- gradable polymers. 2 In this context, biopolymers are considered potential replacements for conventional plastic materials; never- theless, some of their properties must be improved to position them as materials that can be competitive with fossil derivatives, especially their poor mechanical, thermal, and barrier properties. 3 The use of natural polymers has several advantages including non-toxicity, biodegradability, wide availability, and biocompati- bility, especially when compared to their synthetic counterparts. 2 Chitosan (CS) is a linear polysaccharide and deacetylated deriva- tive of chitin. 4 This biopolymer is among the most important natural polymers due to its diverse spectrum of applications that range from pharmaceuticals to materials science. 5–8 However, some obstacles hinder CS’s extensive use, particularly, its rela- tively lower elongation, low toughness properties, high degree of swelling in water, relatively poor water vapor barrier characteris- tics as well as its high price compared to conventional plastics. 9,10 In an effort to overcome these scientific and technological chal- lenges, several attempts have been made to improve the properties of CS, particularly for the CS-based film. For example, to improve the mechanical and functional properties of CS film, several syn- thetic polymers have been blended with CS such as poly(vinyl Additional Supporting Information may be found in the online version of this article. V C 2015 Wiley Periodicals, Inc. WWW.MATERIALSVIEWS.COM J. APPL. POLYM. SCI. 2015, DOI: 10.1002/APP.42004 42004 (1 of 13)